结冷胶-黑米花青素-二氧化钛复合膜在蓝莓涂膜保鲜中的应用研究

以结冷胶、黑米花青素、二氧化钛为原料制备了可食性复合膜液，并利用复合膜液对蓝莓进行涂膜保鲜实验，研究新型复合膜对蓝莓的保鲜效果。首先，扫描电子显微镜发现结冷胶膜（GG）、结冷胶-黑米花青素复合膜（GG-BRA）和结冷胶-黑米花青素-二氧化钛复合膜（GG-BRA-TiO2）的横截面无明显裂缝、无分层现象，傅里叶红外光谱进一步表明结冷胶可以通过非共价键与黑米花青素和二氧化钛进行相互作用。抑菌实验发现结冷胶-黑米花青素-二氧化钛复合膜（GG-BRA-TiO2）具有良好的抑菌性，其中对金黄色葡萄球菌、大肠杆菌和面包酵母的抑菌圈分别为4.14、2.77 和3.55mm。其次，利用复合膜液对蓝莓进行涂膜保鲜实验，结果表明GG-BRA和GG-BRA-TiO2涂膜组能减缓蓝莓果实贮藏过程中的物理化学性质的变化速率，其中GG-BRA-TiO2的延缓效果优于GG-BRA。经贮藏10 d，GG-BRA-TiO2膜组的蓝莓失重率、硬度、花色苷、总酚、多酚氧化酶活力的下降分别较空白对照减少了1.56%、23.69%、18.44%、12.71%、14.00%，因此GG-BRA-TiO2复合膜可作为良好的涂膜保鲜材料应用于食品包装材料中。

Application of Gellan Gum-black Rice Anthocyanin-titanium Dioxide Composite Film in the Coating Preservation of Blueberry

An edible film using gellan gum, black rice anthocyanins, and titanium dioxide as raw materials were prepared. The effect of edible film on blueberries coating preservation was investigated. Firstly, scanning electron microscopy revealed that there were no obvious cracks or delamination in the cross sections of the gellan gum film (GG), gellan gum, and black rice anthocyanin, composite film (GG-BRA), and gellan gum, black rice anthocyanin, and titanium dioxide composite film (GG-BRA-TiO2). Fourier transform infrared spectroscopy further showed that gellan gum was interacted with black rice anthocyanin and titanium dioxide through non covalent bond. The antibacterial experiment indicated that the GG-BRA-TiO2 composite film had a good antibacterial activity, in which size of the antibacterial circle for Staphylococcus aureus, E. coli and bread''s yeast were 4.14, 2.77 and 3.55 (mm), respectively. Secondly, the composite film was used for the preservation of blueberries. The results showed that the GG-BRA and GG-BRA-TiO2 coating groups could slow down the rate of physicochemical properties changes during blueberry fruit storage. Among them, the preservation effect of GG-BRA-TiO2 composite film was better than that of GG-BRA composite film. After 10 days of storage, the weight loss rate, hardness, anthocyanins, total phenols, and the activity of polyphenol oxidase were decreased by 1.56%, 23.69%, 18.44%, 12.71%, and 14.00% compared to the control group, respectively. Therefore, GG-BRA-TiO2 composite film showed good water resistance and antibacterial properties and could be used as a promising coating and preservation material in food packaging.